From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Chris Barber
Sent: Friday, January 24, 2014 1:38 AM
To: Rotary motors in aircraft
Subject: [FlyRotary] Velocity tire blow out

Well, on one hand I am pleased that when I did a quick loop of the pattern after I got off work this morning (I just switched to graveyard shift this week so get off work at 0700 hrs) my rotary ran smooth and strong and seemed to be producing pretty kick ass power.

HOWEVER, when I landed, I had my starboard tire blow out. Yes, it is quite the attention getter. I swayed slightly to the right of center of the runway at LVJ and luckily exited the taxiway closest to my hangar.

I was able to get it back to the hangar. No damage to the aircraft this time, not even the tire rim. But, I noted I had excessive wear on the inside of the tire.....much more than i would have expected with only 15 landings and less than seven hours of flight. I have done extensive taxi testing though (basically having and expensive go-cart)

I had noted on my conditional inspection that I had uneven wear but it did not seem that bad and I pledged to mind it. I concluded that the uneven wear on the inner tire was due to the gear spread that I had noticed on my and other canards (my hangar mate has a long easy and he is always lifting his bird to get the gear from spreading after taxi).

Velocity is pretty specific on how to set the camber and recommend you set the camber after installing the engine and wings, which I did.

When the gear is not spread, the tires set directly in the center "meat" of the tire. However, I have now noted...with the consequences, that as the gear spreads, there is a significant tilt to the inner edge of the tires thus causing the wear.

The gear bow is provided in the Velocity kit and it quite sturdy. What am I missing regarding the bow spread tilting the tire to the inside of the tire, thus wearing in what would seem a less wear prone area? I am certain the camber was proper when the gear is not spreading out. I remember how tedious it was setting it, lowering the plane, checking, lifting, setting, lowering, checking repeat a number of times to ensure the proper set (same goes to the toe-in process), but it is significant enough from the spread to roll the tire on the inner edge to cause a problem.

Before I drop a few hundred on new tire and tube and try to fly again, I would like to figure out what I need to address. Is it just to re-set the camber to be on the center meat of the tire when spread since this seems to be the case when taxiing or is there something else?

Insight guys???? Discuss.

Thanks,

Chris